… many scripts ready for the task. Snapshots work best with InnoDB, with MyISAM you’ll have to start the snapshot while…, maybe it is related to better raid controller write cache use. Even the fairly slow gzip-1 mode works well. The tpcc… ray flip a bit on a drive, instead of crashing InnoDB, it will be caught by ZFS and the data will…
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
… –session-init-query command-line option, we set the option innodb_fake_changes to prevent INSERTs, UPDATEs, and DELETEs from corrupting… server. You will need Percona Server in order to use innodb_fake_changes. Thread pool Percona Playback added a connection pool… duplicate key errors may be faster than an actual database write. The slow logs were split into chunks, each containing roughly 1M…
Post: Percona XtraBackup 2.1.0 'release candidate' for MySQL available for download
May 7, 2013 By Leave a Comment
… the 2.0 series at the time of writing). New Features: This version of Percona XtraBackup has… files). Percona XtraBackup has implemented support for the InnoDB Buffer Pool Preloading introduced in MySQL 5.6…. #1079135. If there are thousands of tables and slow IO then XtraBackup can spend a lot of…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…Innodb_buffer_pool_write_requestsblogpercona.commanual innodb_change_bufferingblogpercona.commanual innodb_checksumsblogpercona.commanual innodb_commit_concurrencyblogpercona.commanual innodb_concurrency_ticketsblogpercona.commanual innodb_data_file_pathblogpercona.commanual Innodb…
Post: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
…), your database fits into memory, and your write rate is significant, then the slow disk is, by definition, not able to… perform sequential writes where possible and avoid random writes, which is quite critical for hard drives. What we found is that InnoDB does… how it works, instead of performing 1 random write, InnoDB will perform 8 random writes. I do not have a good explanation for…
Post: A (prototype) lower impact slow query log
September 20, 2012 By 12 Comments
… case of writing the slow query log, if we had a buffer that was the log entry, we could just call write(2… write(2)ing to then bad things may happen (namely that the file descriptor gets reused for something else.. say an innodb data file, and writing part of your slow query log as an innodb page will not end in…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… time object will be free already. OS Waits are relatively slow, and if you get tens of thousands of OS waits… value your log writes may be more or less expensive. If innodb_flush_logs_at_trx_commit=2 log writes are done to OS cache, and being sequential writes these logs writes are pretty…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… smaller) or can a bit slow it down. Plus there were bunch of micro optimizations in Innodb in 5.0 series. Also… from 8Gig to 16Gig help the write performance of Innodb on Solaris? HT: Yes, if your ‘write working set’ fits in 16 GB… memory for write buffering efficiently. Q30: Question about using solid state disks for storing ib_log* files; I know that innodb writes files…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
… tablespaces. Ultimately this mechanism was an optimization for slow drives: if you can sequentially write all the changes into a log, it…, so Innodb does not permit such an operation and will block incoming writes until the space is available to continue (safely) writing in… and writes to the transaction log if you set this too high. innodb_write_io_threads: Controls how many threads will have writes in…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… which slows down throughput. If we could control the checkpointing rate we could use an 8G write ahead log and tell innodb to do a full write of the database (basically dump memory… optimizations to work – Innodb would also need also to write not-modified pages if this will get sequential write. Say if we have…
